This invention relates to monitoring systems, and more particularly to systems for monitoring certain parameters of the operation of systems of the general type described in, for example, U.S. Pat. Nos. 5,632,816; 5,746,831; and 5,787,928. However, the system of the invention is believed to be useful in other applications as well. The disclosures of U.S. Pat. Nos. 5,632,816; 5,746,831; and 5,787,928 are hereby incorporated herein by reference.
Many voltage blocks are illustrated and described in the prior art. There are, for example, the voltage blocks illustrated and described in U.S. Pat. Nos. 4,878,622; 4,982,903; 5,033,942; 5,154,357; and 5,193,750, and the references cited in those patents, particularly including U.S. Pat. No. 1,655,262; 2,547,440; 2,673,232; 3,098,890; 3,122,320; 3,291,889; 3,893,620; 3,933,285; 3,934,055; 4,017,029; 4,020,866; 4,085,892; 4,275,834; 4,313,475; 4,383,644; and, 4,413,788, and U.K. Patent Specifications 1,393,333 and 1,478,853. Also of interest are U.S. Patents: 2,814,551; 2,921,604; 3,419,827; 3,450,092; 3,838,946; 4,030,860; 4,232,055; 4,304,252; 4,381,180; 4,386,888; 4,515,516; 4,552,334; 4,741,673; 4,792,092; 4,879,137; 4,881,688; 4,884,745; 4,932,589; 4,962,724; 5,078,168; 5,094,389; 5,096,126; 5,102,045; 5,102,046; 5,105,851; 5,197,676; 5,244,012; 5,249,748; 5,255,856; 5,273,072; 5,288,029; 5,288,525; 5,326,031; 5,340,289; 5,341,990; and, 5,364,035. The disclosures of these references also are hereby incorporated herein by reference. No representation is intended by this listing that this is a complete listing of all pertinent prior art, or that a thorough search of all pertinent prior art has been conducted, or that no better prior art exists. Nor should any such representation be inferred.
According to the invention, a coating system includes a source of electrically non-insulative coating material, a dispenser for dispensing the coating material toward an article to be coated thereby, and an electrostatic high potential supply for supplying charge to the coating material. The high potential supply is coupled across the dispenser and the article. The coating system further includes a reservoir, a valve having a housing providing first, second, third and fourth ports, and a component movable within the housing and having a first passageway selectively to connect the first port to the second port to permit the flow of coating material between the first port and the second port. The first port is coupled to the coating material source. The second port is coupled to the reservoir. The third port is coupled to the dispenser. The component is movable within the housing selectively to connect the second port to the third port to permit the flow of coating material between the reservoir and the dispenser. The coating system includes a source of an electrically non-conductive fluid. The housing and the first movable component define between them a second passageway. The source of electrically non-conductive fluid is coupled to the fourth port to provide a flow of the electrically non-conductive fluid from the source of electrically non-conductive fluid through the second passageway to flush coating material from surfaces of the housing and movable component adjacent the second passageway.
According to one aspect of the invention, the apparatus further includes a sensor for sensing a flow rate of the electrically non-conductive fluid and providing an indication when the flow rate of the electrically non-conductive fluid falls outside a desired range.
According to another aspect of the invention, the apparatus further includes a sensor for sensing a pressure of the electrically non-conductive fluid and providing an indication when the pressure of the electrically non-conductive fluid falls outside a desired range.
According to another aspect of the invention, the apparatus further includes a sensor for sensing a pressure of the coating material and providing an indication when the pressure of the coating material falls outside a desired range.
According to another aspect of the invention, the apparatus further includes a sensor for sensing the current supplied from the potential supply through the valve and providing an indication when the current supplied from the potential supply through the valve falls outside a desired range.
According to another aspect of the invention, the apparatus further includes a source of compressed gas for use in operating at least one of the source of electrically non-insulative coating material, the dispenser, the reservoir, the valve, and the source of electrically non-conductive fluid. The source of compressed gas is coupled to the at least one of the source of electrically non-insulative coating material, the dispenser, the reservoir, the valve, and the source of electrically non-conductive fluid. A sensor is provided for sensing a pressure of the compressed gas and providing an indication when the pressure of the compressed gas falls outside a desired range.